This invention relates to a method and apparatus for preheating scrap metal with metalurgical furnace waste gases and more particularly to the purification and removal of such gases.
Electric arc furnaces employed for steel production are relatively large in size and produce large quantities of poluting gases. In order to prevent the direct discharge of such gases into the atmosphere, dust collecting equipment are normally installed in connection with electric arc furnaces. With the recent sharp rise in power costs, these electric arc furnace discharge gases have been employed for preheating scrap as an energy saving measure. This is accomplished by directly contacting scrap to be preheated with the high temperature waste gases evacuated from the furnace.
When electric arc furnace waste gases have been employed for scrap preheating, secondary pollution has occurred as a result of the incomplete combustion of the impurities and oily substances adhering to the surface of the scrap and which are released during preheating.